A variety of reasons, really.
First of all, the name.
I really don't like the sound of it. No matter which way you render it, "dogme" -- as per the Danish and the original Dogme 95 film movement, or "dogma" -- which is what the Danish word actually translates to, on the one hand you get a word with unfortunate orthographic or even onomatopoeic associations, and on the other you get a word that denotes stifling, stubbornly held beliefs or doctrines which are authoritative and not to be disputed or doubted.
However valuable or interesting the principles (or "vows of chastity") associated with Dogme ELT are, if you think I am ever going to announce in a teacher's room or workshop (with new teachers and/or teachers completely unfamiliar with Scott Thornbury and his wicked(ly good) objections to coursebook-dominated language teaching) that I'm a fan of "dogmatic" teaching, or "dog me" or "dogma" teaching for that matter, you've got another thing coming.
I know the idea behind Dogme ELT was inspired by the Danish film movement of the same name. I get it. I also have a lot of respect for the Dogme ELT movement and their discussion forum. But I stand by my belief that it is a rather unfortunate name. One that I think unnecessarily inhibits its potential for growth and dissemination beyond a sort of anti-establishment club of very experienced teachers.
Now... teaching unplugged? There's a good name!
Slightly unfortunate that it may associate itself with being anti-technology, but easier to explain and without any unfortunate onomatopoeic or religious associations.
And with the excellent award-winning resource book from Thornbury and Meddings, I like the fact that Teaching Unplugged has toned down some of its rhetoric somewhat. "Vows of Chastity" have become general principles. Instead of coming across as an anti-coursebook movement, we now have talk of exploring "unplugged teaching moments" alongside (or even inside) coursebook oriented courses. There even appears to be some measure of acceptance that technology can play a positive role in unplugged language teaching -- though admittedly that (like everything else here) can depend a little bit on whom you are reading/listening to and when.
Anyway, teaching unplugged (or unplugged teaching) it is for me.
No offense or disrespect meant to the Dogme folks of course. It's just a word/name that doesn't work for me, and I hope you will forgive me if I don't use it all that much on this blog (or in the staffroom).